Answer:
1). Doctors diagnose over 20,000 patients with diabetes each year in the United States. (Passive to Active).
2). The extract from Sample A to Sample B was added (by us) to create a mixture. (Active to Passive).
3). The scribes and scholars have written Encyclopedias throughout history. (Passive to Active).
4). The results were assessed (by our team) using a Chi-square statistic. (Active to passive).
5). The embryos were stored (by us) in a cryogenic tank for two weeks. (Active to passive).
Step-by-step explanation:
'Active Voice' is described as the grammatical formation in which the subject is undertaking the particular action expressed by the verb. In 'Passive Voice,' the subject receives the action instead of performing it. In the former, the emphasis is on the 'subject' while in the latter, the focus shifts to the object and the verb's action. Therefore, the subject can even be omitted in 'passive voice' as it will not affect the meaning of the sentence. The structure of active and passive voices are as follows:
Active voice - 'Subject + helping verb + main verb + object.'
Passive Voice - 'Object + helping verb + main verb + by + subject.'